Computer systems typically comprise a number of boards (also referred to as cards or modules) on which resides the electrical components such as processors, memory, application-specific integrated circuits, etc. In powering such systems, there is typically a power system comprising one, or more, power supplies and a power distribution system, or power bus, for coupling each of the boards to the power supplies. The latter provide a variety of different voltages used in the computer system, such as but not limited to +5 volts (V), +12V, −5V, −12V, 3.3V, 1.8V, 1.5V, 48V, etc. (It should also be noted that there may be supplementary power supplies for providing a certain level of redundancy for the power system.)
Typically, such a power system provides what is referred to as “central power control” of individual voltage levels for performing maintenance and trouble-shooting of the computer system. In other words, an individual voltage level, e.g., the +5 volt level, can be monitored and adjusted for the entire computer system (also referred to as a “domain”). Such monitoring or adjustment can occur either directly (e.g., via a knob on the respective power supply, or via a local system administration terminal) or indirectly (e.g., where the system administration terminal is located at a remote location and coupled to the computer system via, e.g., an intranet). Thus, e.g., it is possible to raise, or lower, a particular voltage level, e.g., +5V, to all the boards of the computer system at once.